Faulty coils are costing me money!

I raised my concern with Twisp via their website on 17 July 2019. Up to date, NO reply. On 25/06 I bought a Clearo 2 starter pack. BOTH the coils were faulty. Another coil was bought, which only lasted 2 weeks. Another coil was bought on 6 July 2019, and yet again only lasted 2 weeks. On 27 July 2019 2 more coils were bought, and to my disgust the 1st one only lasted 2 weeks and when opening the 2nd 1 it was once again faulty! Another coil was bought on 07/08/2019 - this 1 is working, but for how long, one wonders. I have been a Twisp client for years, and never have I ever experienced this before.